// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.
 
using System.Threading.Tasks;
 
namespace Roslyn.Utilities;
 
internal static class ValueTaskExtensions
{
    /// <summary>
    /// Asserts the <see cref="ValueTask"/> passed has already been completed.
    /// </summary>
    /// <remarks>
    /// This is useful for a specific case: sometimes you might be calling an API that is "sometimes" async, and you're
    /// calling it from a synchronous method where you know it should have completed synchronously. This is an easy
    /// way to assert that while silencing any compiler complaints.
    /// </remarks>
    public static T VerifyCompleted<T>(this ValueTask<T> task, string message = "ValueTask should have already been completed")
    {
        Contract.ThrowIfFalse(task.IsCompleted, message);
 
        // Propagate any exceptions that may have been thrown.
        return task.GetAwaiter().GetResult();
    }
}